Unable to generate the model because of the following exception: 'The item with identity 'LLW_CODE' already exists in the metadata collection.
Parameter name: item
'.
Loading metadata from the database took 00:00:04.6467538.
Generating the model took 00:00:36.7599838.
Unable to update the Web.Config file because of the following exception: 'The 'server' keyword is not supported.'
Successfully registered the assembly 'System.Data.Entity, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' in the Web.Config file.

Please try to add a Devart Entity model to your project. Its functionality is the same as the functionality of Microsoft Entity model, and it has a bit more convenient designer and some other features like flexible code generation and editable Storage model.
Please let us know if the error persists.